Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs

Nick Piggin
2004-02-03T03:57:01Z

Philip Martin wrote:

>Nick Piggin <piggin@cyberone.com.au> writes:
>
>
>
>>Philip Martin wrote:
>>
>>
>>
>>>Nick Piggin <piggin@cyberone.com.au> writes:
>>>
>>>
>>>>When the build finishes and there is no other activity, can you
>>>>try applying anonymous memory pressure until it starts swapping
>>>>to see if everything gets reclaimed properly?
>>>>
>>>>
>>>How do I apply anonymous memory pressure?
>>>
>>>
>>Well just run something that uses a lot of memory and doesn't
>>do much else. Run a few of these if you like:
>>
>>#include <stdlib.h>
>>#include <unistd.h>
>>#define MEMSZ (64 * 1024 * 1024)
>>int main(void)
>>{
>> int i;
>> char *mem = malloc(MEMSZ);
>> for (i = 0; i < MEMSZ; i+=4096)
>> mem[i] = i;
>> sleep(60);
>> return 0;
>>}
>>
>>
>
>This is what free reports after the build
>
> total used free shared buffers cached
>Mem: 516396 215328 301068 0 85084 68364
>-/+ buffers/cache: 61880 454516
>Swap: 1156664 40280 1116384
>
>then after starting 10 instances of the above program
>
> total used free shared buffers cached
>Mem: 516396 513028 3368 0 596 5544
>-/+ buffers/cache: 506888 9508
>Swap: 1156664 320592 836072
>
>and then after those programs finish
>
> total used free shared buffers cached
>Mem: 516396 35848 480548 0 964 5720
>-/+ buffers/cache: 29164 487232
>Swap: 1156664 54356 1102308
>
>It looks OK to me.
>
>
>

Yeah thats looks fine. It was a wild guess.